Determination of groundwater flow regimes based on the spatial non-local distribution of hydraulic gradient:Model and validation

作     者：Xiu-xuan Wang Jia-zhong Qian Lei Ma Qian-kun Luo Guan-qun Zhou 

作者机构：School of Resources and Environmental EngineeringHefei University of TechnologyHefei230009China 

出 版 物：《Journal of Hydrodynamics》 (水动力学研究与进展B辑（英文版）)

年 卷 期：2022年第34卷第2期

页      面：299-307页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 080103[工学-流体力学] 0815[工学-水利工程] 0705[理学-地理学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China(Grants Nos.41831289 41877191 42072276). 

主　　题：Hydraulic head distribution spatially non-local effect flow regime Forchheimer number Reynolds number 

摘      要：The groundwater flow in natural aquifers can change from the Darcy flow to the non-Darcian flow due to a variety of causes,such as the increase of the Reynolds number in the highly permeable media or the decrease of the hydraulic gradient below a threshold in the low-permeability media,while the representative flow regime cannot be reliably determined using the traditional criteria.To address this challenge,this paper proposes a new term called the equivalent hydraulic gradient(EHG)by generalizing the differential form of the Darcy’s law using a spatial integral of the upstream hydraulic head.The nonlocal spatial variation of the hydraulic head difference between upstream and downstream zones is assumed to be the potential cause of the transition of the groundwater flow regimes.This assumption is analogous to the common assumption used for quantifying the anomalous pollutant transport in the geological media.Applications of this idea show that the EHG concept could distinguish three main flow regimes,namely the Super-Darcy flow,the Darcy flow,and the Sub-Darcy flow,although the Super-Darcy flow regime is rarely observed in the laboratory column flow experiments.Results of this study therefore shed lights on the interpretation of the fundamental dynamics of the groundwater moving in various heterogeneous aquifers,and may lead to the rebuilding of the hydrodynamics of the surface water,the groundwater,and the soil.